Radio frequency waveguide communication in high temperature environments

ABSTRACT

A system includes a network of nodes. A controller of the system is operable to communicate with the network of nodes through one or more electromagnetic signals. A plurality of waveguides is configured to guide transmission of the one or more electromagnetic signals. A radio frequency transceiver is configured to establish communication between the controller and a first waveguide of the plurality of waveguides. A membrane is configured to support communication between the first waveguide and at least one node of the plurality of nodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/086,588 filed Nov. 2, 2020, which claims the benefit of U.S. patentapplication Ser. No. 16/692,125 filed Nov. 22, 2019, issued as U.S. Pat.No. 10,826,547 issued Nov. 3, 2020, the disclosures of which areincorporated by reference herein in its entirety.

BACKGROUND

This disclosure relates to electromagnetic communication, and moreparticularly to a radio frequency waveguide communication in hightemperature environments.

As control and health monitoring systems become more complex, theinterconnect count between system components increases, which alsoincreases failure probabilities. With the increase in interconnects,troubleshooting systems may not always identify the contributing faultycomponents reliably when system anomalies occur. Failures associatedwith such systems are often due to connection system failures,including: sensors, wiring, and connectors that provide interconnection(e.g., signal and power) between all components.

Difficulties can arise when troubleshooting these complex interconnectedsystems, especially when the systems include subsystems havingelectronic components connected to control system devices, such asactuators, valves or sensors. For example, a noisy signal in a sensorreading could be caused by a faulty interface circuit in the electroniccomponent, a faulty wire or short(s) in the cable system, and/or afaulty or intermittent sensor. The time associated with identifying afaulty component quickly and accurately affects operational reliability.

Detailed knowledge of machinery operation for control or healthmonitoring requires sensing systems that need information from locationsthat are sometimes difficult to access due to moving parts, internaloperating environment or machine configuration. The access limitationsmake wire routing bulky, expensive and vulnerable to interconnectfailures. The sensor and interconnect operating environments for desiredsensor locations often exceed the capability of the interconnectsystems. In some cases, cable cost, volume and weight exceed the desiredlimits for practical applications.

Application of electromagnetic sensor and effector technologies toaddress the wiring constraints faces the challenge of providing reliablecommunications in a potentially unknown environment with potentialinterference from internal or external sources. Large-scale deploymentsof multiple sensors and/or effectors with varying signal path lengthsfurther increases the challenges of normal operation and fault detectionin a network of connected nodes. High temperature environments furtherconstrain communication system components.

BRIEF DESCRIPTION

According to one embodiment, a system includes a network of nodes. Acontroller of the system is operable to communicate with the network ofnodes through one or more electromagnetic signals. A plurality ofwaveguides is configured to guide transmission of the one or moreelectromagnetic signals. A radio frequency transceiver is configured toestablish communication between the controller and a first waveguide ofthe plurality of waveguides. A membrane is configured to supportcommunication between the first waveguide and at least one node of theplurality of nodes.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the firstwaveguide is a hollow metallic waveguide.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include a dielectric disk inthe first waveguide proximate to the membrane, where the dielectric diskis configured to generate a plurality of acoustic pressure waves tomechanically vibrate the membrane responsive to the pulse trainbroadcast through the first waveguide, and the at least one nodeincludes an effector node.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the at leastone node includes an oscillator and a modulator configured to vibratethe membrane based on a sensor response, and the radio frequencytransceiver is configured to detect vibration of the membrane.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include a dielectric ring inthe first waveguide proximate to the membrane, where the dielectric ringis configured to generate a plurality of acoustic pressure waves tomechanically vibrate the membrane responsive to the pulse trainbroadcast through the first waveguide, and the at least one nodeincludes an effector and sensor node.

According to an embodiment, a system for a gas turbine engine includes anetwork of a plurality of nodes distributed throughout the gas turbineengine. Each of the nodes is associated with at least one sensor and/oreffector of the gas turbine engine and is operable to communicatethrough one or more electromagnetic signals. A controller of the gasturbine engine is operable to communicate with the network of nodesthrough the one or more electromagnetic signals. A plurality ofwaveguides is configured to guide transmission of the one or moreelectromagnetic signals between the controller and one or more of thenodes. A radio frequency transceiver is configured to establishcommunication between the controller and a first waveguide of theplurality of waveguides. A membrane is configured to supportcommunication between the first waveguide and at least one node of theplurality of nodes.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where one or more ofthe nodes are located at least one of a fan section, a compressorsection, a combustor section and a turbine section of the gas turbineengine, and the first waveguide can be a hollow metallic waveguide.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller, and adielectric ring in the first waveguide is proximate to the membrane,where the dielectric ring is configured to generate a plurality ofacoustic pressure waves to mechanically vibrate the membrane responsiveto the pulse train broadcast through the first waveguide, and the atleast one node includes an effector and sensor node.

According to an embodiment, a method of establishing electromagneticcommunication includes configuring a network of a plurality of nodes tocommunicate through a one or more electromagnetic signals. Communicationbetween a controller and the network of nodes is initiated through theone or more electromagnetic signals. Transmission of the one or moreelectromagnetic signals is guided in a plurality of waveguides betweenthe controller and one or more of the nodes. A portion of the one ormore electromagnetic signals propagates through a radio frequencytransceiver configured to establish communication between the controllerand a first waveguide of the plurality of waveguides, and a membrane isconfigured to support communication between the first waveguide and atleast one node of the plurality of nodes.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include outputting a pulsetrain from the radio frequency transceiver to broadcast within the firstwaveguide responsive to the controller.

In addition to one or more of the features described above or below, oras an alternative, further embodiments may include where the at leastone node comprises an oscillator and a modulator, and the methodincludes vibrating the membrane based on a sensor response modulatedwith a carrier frequency of the oscillator by the modulator, anddetecting vibration of the membrane by the radio frequency transceiver.

A technical effect of the apparatus, systems and methods is achieved byusing radio frequency waveguide communication in high temperatureenvironments as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a cross-sectional view of a gas turbine engine as an exampleof a machine;

FIG. 2 is a schematic view of a guided electromagnetic transmissionnetwork in accordance with an embodiment of the disclosure;

FIG. 3 is a schematic view of a communication path through a waveguideto an effector node in accordance with an embodiment of the disclosure;

FIG. 4 is a schematic view of a communication path through a waveguideto a sensor node in accordance with an embodiment of the disclosure;

FIG. 5 is a schematic view of a communication path through a waveguideto an effector and sensor node in accordance with an embodiment of thedisclosure; and

FIG. 6 is a flow chart illustrating a method in accordance with anembodiment of the disclosure.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

Various embodiments of the present disclosure are related toelectromagnetic communication through and to components of a machine.FIG. 1 schematically illustrates a gas turbine engine 20 as one exampleof a machine as further described herein. The gas turbine engine 20 isdepicted as a two-spool turbofan that generally incorporates a fansection 22, a compressor section 24, a combustor section 26 and aturbine section 28. Alternative engines may include an augmentor section(not shown) among other systems or features. The fan section 22 drivesair along a bypass flow path B in a bypass duct to provide a majority ofthe thrust, while the compressor section 24 drives air along a core flowpath C for compression and communication into the combustor section 26then expansion through the turbine section 28. Although depicted as atwo-spool turbofan gas turbine engine in the disclosed non-limitingembodiment, it should be understood that the concepts described hereinare not limited to use with two-spool turbofans as the teachings may beapplied to other types of turbine engines including three-spoolarchitectures or any other machine that requires sensors to operate withsimilar environmental challenges or constraints. Additionally, theconcepts described herein may be applied to any machine or systemcomprised of control and/or health monitoring systems. Examples caninclude various moderate to high temperature environments, such as glassand metal forming systems, petroleum-oil-and-gas (POG) systems,ground-based turbine for energy generation, nuclear power systems, andtransportation systems.

With continued reference to FIG. 1 , the exemplary engine 20 generallyincludes a low speed spool 30 and a high speed spool 32 mounted forrotation about an engine central longitudinal axis A relative to anengine static structure 36 via several bearing systems 38. It should beunderstood that various bearing systems 38 at various locations mayalternatively or additionally be provided, and the location of bearingsystems 38 may be varied as appropriate to the application.

The low speed spool 30 generally includes an inner shaft 40 thatinterconnects a fan 42, a first (or low) pressure compressor 44 and afirst (or low) pressure turbine 46. The inner shaft 40 is connected tothe fan 42 through a speed change mechanism, which in exemplary gasturbine engine 20 is illustrated as a geared architecture 48 to drivethe fan 42 at a lower speed than the low speed spool 30. The high speedspool 32 includes an outer shaft 50 that interconnects a second (orhigh) pressure compressor 52 and a second (or high) pressure turbine 54.A combustor 56 is arranged in exemplary gas turbine engine 20 betweenthe high pressure compressor 52 and the high pressure turbine 54. Amid-turbine frame 58 of the engine static structure 36 is arrangedgenerally between the high pressure turbine 54 and the low pressureturbine 46. The mid-turbine frame 58 further supports bearing systems 38in the turbine section 28. The inner shaft 40 and the outer shaft 50 areconcentric and rotate via bearing systems 38 about the engine centrallongitudinal axis A which is collinear with their longitudinal axes.

The core airflow is compressed by the low pressure compressor 44 thenthe high pressure compressor 52, mixed and burned with fuel in thecombustor 56, then expanded over the high pressure turbine 54 and lowpressure turbine 46. The mid-turbine frame 58 includes airfoils 60 whichare in the core airflow path C. The turbines 46, 54 rotationally drivethe respective low speed spool 30 and high speed spool 32 in response tothe expansion. It will be appreciated that each of the positions of thefan section 22, compressor section 24, combustor section 26, turbinesection 28, and fan drive gear system 48 may be varied. For example,gear system 48 may be located aft of combustor section 26 or even aft ofturbine section 28, and fan section 22 may be positioned forward or aftof the location of gear system 48. In direct drive configurations, thegear system 48 can be omitted.

The engine 20 in one example is a high-bypass geared aircraft engine.Low pressure turbine 46 pressure ratio is pressure measured prior toinlet of low pressure turbine 46 as related to the pressure at theoutlet of the low pressure turbine 46 prior to an exhaust nozzle. Asignificant amount of thrust can be provided by the bypass flow B due tothe high bypass ratio. The example low pressure turbine 46 can providethe driving power to rotate the fan section 22 and therefore therelationship between the number of turbine rotors 34 in the low pressureturbine 46 and the number of blades in the fan section 22 can establishincreased power transfer efficiency.

The disclosed example gas turbine engine 20 includes a control andhealth monitoring system 64 (generally referred to as system 64)utilized to monitor component performance and function. The system 64includes a network 65, which is an example of a guided electromagnetictransmission network. The network 65 includes a controller 66 operableto communicate with nodes 68 a, 68 b through electromagnetic signals.The nodes 68 a, 68 b can be distributed throughout the gas turbineengine 20 or other such machine. Node 68 a is an example of an effectornode that can drive one or more effectors/actuators of the gas turbineengine 20. Node 68 b is an example of a sensor node that can interfacewith one or more sensors of the gas turbine engine 20. Nodes 68 a, 68 bcan include processing support circuitry to transmit/receiveelectromagnetic signals between sensors or effectors and the controller66. A coupler 67 can be configured as a splitter between a waveguide 70coupled to the controller 66 and waveguides 71 and 72 configured toestablish wireless communication with nodes 68 a and 68 b respectively.The coupler 67 can be a simple splitter or may include a repeaterfunction to condition electromagnetic signals sent between thecontroller 66 and nodes 68 a, 68 b. In the example of FIG. 1 , a radiofrequency-based repeater 76 is interposed between the coupler 67 andnode 68 b, where waveguide 72 is a first waveguide coupled to thecoupler 67 and radio frequency-based repeater 76, and waveguide 73 is asecond waveguide coupled to the radio frequency-based repeater 76 andnode 68 b. Collectively, waveguides 70, 71, 72, 73 are configured toconfine transmission of the electromagnetic signals between thecontroller 66 and one or more of the nodes 68 a, 68 b. The transmissionmedia within waveguides 70-73 may include dielectric or gaseousmaterial. In embodiments, the waveguides 70-73 can be hollow metaltubes. The disclosed system 64 may be utilized to control and/or monitorany component function or characteristic of a turbomachine, aircraftcomponent operation, and/or other machines.

Prior control & diagnostic system architectures utilized in variousapplications include centralized system architecture in which theprocessing functions reside in an electronic control module. Redundancyto accommodate failures and continue system operation systems can beprovided with dual channels with functionality replicated in bothcontrol channels. Actuator and sensor communication is accomplishedthrough analog wiring for power, command, position feedback, sensorexcitation and sensor signals. Cables and connections include shieldingto minimize effects caused by electromagnetic interference (EMI). Theuse of analog wiring and the required connections limits application andcapability of such systems due to the ability to locate wires,connectors and electronics in small and harsh environments thatexperience extremes in temperature, pressure, and/or vibration.Exemplary embodiments can use radio frequencies confined to waveguides70-73 in a wireless architecture to provide both electromagnetic signalsand power to the individual elements of the network 65.

The use of electromagnetic radiation in the form of radio waves (MHz toGHz) to communicate and power the sensors and effectors using atraditionally complex wired system enables substantial architecturalsimplification, especially as it pertains to size, weight, and power(SWaP). Embodiments of the invention enable extension of a network wherereduced SNR would compromise network performance by trading off datarates for an expansion of the number of nodes and distribution lines;thereby enabling more nodes/sensors, with greater interconnectivity.

Referring to FIG. 2 , a guided electromagnetic transmission network 100is depicted as an example expansion of the network 65 of FIG. 1 . Theguided electromagnetic transmission network 100 can include thecontroller 66 coupled to coupler 67 through waveguide 170. The coupler67 is further coupled to coupler 67 a through waveguide 171 and tocoupler 67 b through waveguide 172. Coupler 67 a is further coupled tothree nodes 68 a through waveguides 173 a, 173 b, 173 c in parallel.Each of the nodes 68 a can interface or be combined with multipleeffectors 102. Coupler 67 b is also coupled to two nodes 68 b throughwaveguides 174 a, 174 b in parallel. Each of the nodes 68 b caninterface or be combined with multiple sensors 104. Although the exampleof FIG. 2 depicts connections to effectors 102 and sensors 104 isolatedto different branches, it will be understood that effectors 102 andsensors 104 can be interspersed with each other and need not be isolatedon dedicated branches of the guided electromagnetic transmission network100. Couplers 67, 67 a, 67 b can be splitters and/or can incorporateinstances of the radio frequency-based repeater 76 of FIG. 1 . Further,one or more instances of the radio frequency-based repeater 76 can beinstalled at any of the waveguides 170, 171, 172, 173 a-c, and/or 174a-b depending on the signal requirements of the guided electromagnetictransmission network 100.

Nodes 68 a, 68 b can be associated with particular engine components,actuators or any other machine part from which information andcommunication is performed for monitoring and/or control purposes. Thenodes 68 a, 68 b may contain a single or multiple electronic circuits orsensors configured to communicate over the guided electromagnetictransmission network 100.

The controller 66 can send and receive power and data to and from thenodes 68 a, 68 b. The controller 66 may be located on equipment nearother system components or located remotely as desired to meetapplication requirements.

A transmission path (TP) between the controller 66 and nodes 68 a, 68 bcan be used to send and receive data routed through the controller 66from a control module or other components. The TP may utilize electricalwire, optic fiber, waveguide or any other electromagnetic communicationincluding radio frequency/microwave electromagnetic energy, visible ornon-visible light. The interface between the controller 66 and nodes 68a, 68 b can transmit power and signals.

The example nodes 68 a, 68 b may include radio-frequency identification(RFID) devices along with processing, memory and/or the interfaces toconnect to conventional sensors or effectors, such as solenoids orelectro-hydraulic servo valves. The waveguides 170, 171, 172, 173 a-c,and/or 174 a-b can be shielded paths that support electromagneticcommunication, including, for instance, radio frequency, microwaves,magnetic or optic waveguide transmission. Shielding can be provided suchthat electromagnetic energy or light interference 85 withelectromagnetic signals 86 (shown schematically as arrows) are mitigatedin the guided electromagnetic transmission network 100. Moreover, theshielding provides that the electromagnetic signals 86 are less likelyto propagate into the environment outside the guided electromagnetictransmission network 100 and enable unauthorized access to information.In some embodiments, confined electromagnetic radiation is in the range1-100 GHz. Electromagnetic radiation can be more tightly confined aroundspecific carrier frequencies, such as 3-4.5 GHz, 24 GHz, 60 GHz, or76-77 GHz as examples in the microwave spectrum. A carrier frequency cantransmit electric power, as well as communicate information, to multiplenodes 68 a, 68 b using various modulation and signaling techniques.

The nodes 68 a with effectors 102 may include control devices, such as asolenoid, switch or other physical actuation devices. RFID,electromagnetic or optical devices implemented as the nodes 68 b withsensors 104 can provide information indicative of a physical parameter,such as pressure, temperature, speed, proximity, vibration,identification, and/or other parameters used for identifying, monitoringor controlling component operation. Signals communicated in the guidedelectromagnetic transmission network 100 may employ techniques such aschecksums, hash algorithms, error control algorithms and/or encryptionto mitigate cyber security threats and interference.

The shielding in the guided electromagnetic transmission network 100 canbe provided such that power and communication signals are shielded fromoutside interference, which may be caused by environmentalelectromagnetic or optic interference. Moreover, the shielding preventsintentional interference 85 with communication at each component.Intentional interference 85 may take the form of unauthorized datacapture, data insertion, general disruption and/or any other action thatdegrades system communication. Environmental sources of interference 85may originate from noise generated from proximate electrical systems inother components or machinery along with electrostatic and magneticfields, and/or any broadcast signals from transmitters or receivers.Additionally, pure environmental phenomena, such as cosmic radiofrequency radiation, lightning or other atmospheric effects, couldinterfere with local electromagnetic communications.

It should be appreciated that while the system 64 is explained by way ofexample with regard to a gas turbine engine 20, other machines andmachine designs can be modified to incorporate built-in shielding foreach monitored or controlled components to enable the use of a guidedelectromagnetic transmission network. For example, the system 64 can beincorporated in a variety of harsh environment machines, such as anelevator system, heating, ventilation, and air conditioning (HVAC)systems, manufacturing and processing equipment, a vehicle system, anenvironmental control system, and all the like. As a further example,the system 64 can be incorporated in an aerospace system, such as anaircraft, rotorcraft, spacecraft, satellite, or the like. The disclosedsystem 64 includes the network 65, 100 that enables consistentcommunication with electromagnetic devices, such as the example nodes 68a, 68 b, and removes variables encountered with electromagneticcommunications such as distance between transmitters and receivingdevices, physical geometry in the field of transmission, control overtransmission media such as air or fluids, control over air or fluidcontamination through the use of filtering or isolation and knowledge oftemperature and pressure.

The system 64 provides for a reduction in cable and interconnectingsystems to reduce cost and increases reliability by reducing the numberof physical interconnections. Reductions in cable and connecting systemsfurther provides for a reduction in weight while enabling additionalredundancy without significantly increasing cost. Moreover, additionalsensors can be added without the need for additional wiring andconnections that provide for increased system accuracy and response.Finally, the embodiments enable a “plug-n-play” approach to add a newnode, potentially without a requalification of the entire system butonly the new component; thereby greatly reducing qualification costs andtime.

FIG. 3 is a schematic view of a communication path 200 through awaveguide 202 from controller 66 to an effector node 68 a. Thecommunication path 200 can be part of network 65, 100 of FIGS. 1-2 , oranother guided electromagnetic transmission network. The waveguide 202can be one or a plurality of waveguides configured to confinetransmission of the electromagnetic signals. The communication path 200also includes a radio frequency transceiver 204, a radio frequencyantenna 206, a capacitively coupled membrane 208, and a dielectric disk210. The radio frequency antenna 206 can be coupled to a first end ofthe waveguide 202, and the radio frequency transceiver 204 can becoupled between the controller 66 and the radio frequency antenna 206.The capacitively coupled membrane 208 at a second end of the waveguide202 can be configured to establish communication between the waveguide202 and the effector node 68 a. The dielectric disk 210 in the waveguide202 can be proximate to the capacitively coupled membrane 208, where thedielectric disk 210 is configured to generate a plurality of acousticpressure waves to mechanically vibrate the capacitively coupled membrane208 responsive to the pulse train broadcast through the waveguide 202.The controller 66 can transmit control signals (e.g., effector commands)to modulate the pulse train using, for instance, pulse position, pulsewidth, and/or pulse amplitude modulation. In some embodiments, the pulsetrain can be a periodic pulse train.

In exemplary embodiments, the pulse train can include microwave pulses.The waveguide 202 can be hollow and metallic, where the pulses generateacoustic pressure waves inside the dielectric disk 210, which may beelectromagnetically lossy. The dielectric disk 210 can be formed of anengineered material of a desired dielectric constant and/or otherdesired parameters. Excitation by pulses can result in thermoelasticexpansion of the dielectric disk 210, for instance, due to microwaveacoustic effects. Variable acoustic pressure through the dielectric disk210 can be proportional to a control signal causing mechanicalvibrations on the capacitively coupled membrane 208.

The effector node 68 a can include a receiver and driver 212 configuredto convert vibration of the capacitively coupled membrane 208 to anelectrical signal to control an effector 102. Electrical power can beprovided to the receiver and driver 212 and effector 102 using a localpower source or power extracted from electromagnetic signals in thewaveguide 202. For example, signals broadcast in the waveguide 202 caninclude frequencies in different transmission frequency bands to providepower at a different frequency than control signals. Multiple types ofsignals can be transmitted through the waveguide 202 including controland position feedback signals. Although a single instance of waveguide202 and effector node 68 a are depicted in FIG. 3 , there can bemultiple branches of waveguide 202 to support multiple effectors 102 invarious locations. Branching of the waveguide 202 can be achieved usingcouplers 67, 67 a, 67 b of FIG. 2 , for example.

FIG. 4 is a schematic view of a communication path 220 through waveguide222 from a sensor node 68 b to controller 66. The communication path 220can be part of network 65, 100 of FIGS. 1-2 , or another guidedelectromagnetic transmission network. The waveguide 222 can be one or aplurality of waveguides configured to confine transmission of theelectromagnetic signals. The communication path 220 can also includeradio frequency transceiver 204, radio frequency antenna 206, andcapacitively coupled membrane 208. The radio frequency transceiver 204can be a radar-type transceiver configured to detect displacement of thecapacitively coupled membrane 208 by measuring a distance and changes indistance responsive to vibrations of the capacitively coupled membrane208. The radio frequency antenna 206 can be coupled to a first end ofthe waveguide 222, and the radio frequency transceiver 204 can becoupled between the controller 66 and the radio frequency antenna 206.The capacitively coupled membrane 208 at a second end of the waveguide222 can be configured to establish communication between the waveguide222 and the sensor node 68 b.

The sensor node 68 b can include an oscillator 226 and a modulator 228configured to vibrate the capacitively coupled membrane 208 based on asensor 104 response. The radio frequency transceiver 204 can beconfigured to detect vibration of the capacitively coupled membrane 208.The modulator 228 can produce amplitude modulation at the capacitivelycoupled membrane 208, where input from the sensor 104 is modulated bythe modulator 228 with a carrier frequency of the oscillator 226. Aradio frequency distance signal can be received at the radio frequencytransceiver 204 as a proportional signal generated by the sensor 104.The oscillator 226 and modulator 228 can be made of high-temperaturecapable materials using, for example passive elements and/orsemiconductor diodes to survive high temperatures, such as an enginecore. Materials for high-temperature application can include siliconcarbide, gallium nitride, aluminum nitride, aluminum scandium nitride,and other such materials. Components of the sensor node 68 b can belocally powered or powered by energy extracted from electromagneticsignals in the waveguide 222. For example, the radio frequencytransceiver 204 can broadcast power and control signals and receiveencoded sensor signals at different frequencies. The use of differentfrequencies for multiple sensors 104 can enable parallel dataacquisition. Frequencies can be set by different oscillators 226.

FIG. 5 is a schematic view of a communication path 240 through awaveguide 242 between controller 66 and an effector and sensor node 68.The communication path 240 can be part of network 65, 100 of FIGS. 1-2 ,or another guided electromagnetic transmission network. The waveguide242 can be one or a plurality of waveguides configured to confinetransmission of the electromagnetic signals. The communication path 240can also include radio frequency transceiver 204, radio frequencyantenna 206, and capacitively coupled membrane 208. The radio frequencyantenna 206 can be coupled to a first end of the waveguide 242, and theradio frequency transceiver 204 can be coupled between the controller 66and the radio frequency antenna 206. The capacitively coupled membrane208 at a second end of the waveguide 242 can be configured to establishcommunication between the waveguide 242 and the sensor node 68. Thewaveguide 242 can include a dielectric ring 244 with an aperture 246proximate to the capacitively coupled membrane 208, where the dielectricring 244 is configured to generate a plurality of acoustic pressurewaves to mechanically vibrate the capacitively coupled membrane 208responsive to a pulse train broadcast through the waveguide 242. Thecapacitively coupled membrane 208 can be coupled to a transceiver 248configured to communicate with at least one effector 102 and at leastone sensor 104. The aperture 246 of the dielectric ring 244 can providea direct path between the capacitively coupled membrane 208 and theradio frequency antenna 206 for transmitting sensor data of the sensor104 back to the radio frequency transceiver 204, while dielectricmaterial of the dielectric ring 244 can enhance transmission of commandsfor the effector 102 from the radio frequency transceiver 204 to thetransceiver 248. Commanding the effector 102 and data collection fromthe sensor 104 can be performed as previously described in theconfigurations of FIGS. 3 and 4 .

FIG. 6 is a flow chart illustrating a method 300 of establishingelectromagnetic communication through a machine, such as the gas turbineengine 20 of FIG. 1 in accordance with an embodiment. The method 300 ofFIG. 6 is described in reference to FIGS. 1-5 and may be performed withan alternate order and include additional steps. For purposes ofexplanation, the method 300 is primarily described in reference to FIG.1 but can also be implemented on the guided electromagnetic transmissionnetwork 100 of FIG. 2 and other network variations and a variety ofmachines. The machine may operate in or produce a high-temperatureenvironment (e.g., >150 degrees C.) beyond the normal range ofmicroelectronics, which is typically less than 100 degrees C. The localtemperature at different sections of the machine can vary substantially,such as upstream from combustion, at a fuel combustion location, anddownstream from combustion.

At block 301, a network 65 of a plurality of nodes 68 a, 68 b can beconfigured to communicate through a plurality of electromagneticsignals, where the nodes 68 a, 68 b are distributed throughout amachine, such as the gas turbine engine 20. Multiple nodes 68 a, 68 bcan be used in a complete system 64 to take advantage of architecturescalability. Each of the nodes 68 a, 68 b can be associated with atleast one effector 102 or senor 104 of the gas turbine engine 20. Forexample, one or more of the nodes 68 a, 68 b can be located at least oneof a fan section 22, a compressor section 24, a combustor section 26,and/or a turbine section 28 of the gas turbine engine 20.

At block 302, a controller 66 can initiate communication with thenetwork 65 of nodes 68 a, 68 b through the electromagnetic signals, suchas electromagnetic signals 86. Specific tones can be used to targetdesired end-points in the network 65.

At block 303, transmission of the electromagnetic signals is confined ina plurality of waveguides 70-73, 202, 222, 242 between the controller 66and one or more of the nodes 68 a, 68 b. The waveguides 70-73, 202, 222,242 can include a waveguide medium, such as a gas or dielectric. Thewaveguide medium can be a fluid used by the machine, such as fuel, oilor other fluid in the gas turbine engine 20. Alternatively, thewaveguide medium can be an engineered material to supportelectromagnetic communication. Further, the waveguide medium can be air.

At block 304, a portion of the electromagnetic signals can be propagatedthrough a radio frequency antenna 206 coupled to a first end of a firstwaveguide 202, 222, 242 of the plurality of waveguides 70-73, 202, 222,242. A radio frequency transceiver 204 is coupled between the controller66 and the radio frequency antenna 206. A capacitively coupled membrane208 at a second end of the first waveguide 202, 222, 242 can beconfigured to establish communication between the first waveguide 202,222, 242 and at least one node 68, 68 a, 68 b of the plurality of nodes68, 68 a, 68 b.

A pulse train can be output from the radio frequency transceiver 204 tothe radio frequency antenna 206 to broadcast within the first waveguide202, 222, 242 responsive to the controller 66. As previously describedwith respect to FIG. 3 , a plurality of acoustic pressure waves can begenerated to mechanically vibrate the capacitively coupled membrane 208responsive to the pulse train broadcast through the first waveguide 202and the dielectric disk 210. With respect to FIG. 4 , the capacitivelycoupled membrane 208 can vibrate based on a sensor response through theoscillator 226 and modulator 228, and vibration of the capacitivelycoupled membrane 208 can be detected by the radio frequency transceiver204. With respect to FIG. 5 , a plurality of acoustic pressure waves canbe generated by the dielectric ring 244 to mechanically vibrate thecapacitively coupled membrane 208 responsive to the pulse trainbroadcast through the first waveguide 242.

The term “about” is intended to include the degree of error associatedwith measurement of the particular quantity based upon the equipmentavailable at the time of filing the application. For example, “about”can include a range of ±8% or 5%, or 2% of a given value.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,element components, and/or groups thereof.

While the present disclosure has been described with reference to anexemplary embodiment or embodiments, it will be understood by thoseskilled in the art that various changes may be made and equivalents maybe substituted for elements thereof without departing from the scope ofthe present disclosure. In addition, many modifications may be made toadapt a particular situation or material to the teachings of the presentdisclosure without departing from the essential scope thereof.Therefore, it is intended that the present disclosure not be limited tothe particular embodiment disclosed as the best mode contemplated forcarrying out this present disclosure, but that the present disclosurewill include all embodiments falling within the scope of the claims.

What is claimed is:
 1. A system comprising: a network of nodes; acontroller operable to communicate with the network of nodes through oneor more electromagnetic signals; a plurality of waveguides configured toguide transmission of the one or more electromagnetic signals; a radiofrequency transceiver configured to establish communication between thecontroller and a first waveguide of the plurality of waveguides; and amembrane configured to support communication between the first waveguideand at least one node of the plurality of nodes.
 2. The system of claim1, wherein the first waveguide comprises a hollow metallic waveguide. 3.The system of claim 1, wherein the radio frequency transceiver isconfigured to output a pulse train to broadcast within the firstwaveguide responsive to the controller.
 4. The system of claim 3,further comprising a dielectric disk in the first waveguide proximate tothe membrane, wherein the dielectric disk is configured to generate aplurality of acoustic pressure waves to mechanically vibrate themembrane responsive to the pulse train broadcast through the firstwaveguide, and the at least one node comprises an effector node.
 5. Thesystem of claim 1, wherein the at least one node comprises an oscillatorand a modulator configured to vibrate the membrane based on a sensorresponse, and the radio frequency transceiver is configured to detectvibration of the membrane.
 6. The system of claim 5, wherein the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller.
 7. The systemof claim 6, further comprising a dielectric ring in the first waveguideproximate to the membrane, wherein the dielectric ring is configured togenerate a plurality of acoustic pressure waves to mechanically vibratethe membrane responsive to the pulse train broadcast through the firstwaveguide, and the at least one node comprises an effector and sensornode.
 8. A system for a gas turbine engine, the system comprising: anetwork of a plurality of nodes distributed throughout the gas turbineengine, each of the nodes associated with at least one sensor and/oreffector of the gas turbine engine and operable to communicate throughone or more electromagnetic signals; a controller of the gas turbineengine operable to communicate with the network of nodes through the oneor more electromagnetic signals; a plurality of waveguides configured toguide transmission of the one or more electromagnetic signals betweenthe controller and one or more of the nodes; a radio frequencytransceiver configured to establish communication between the controllerand a first waveguide of the plurality of waveguides; and a membraneconfigured to support communication between the first waveguide and atleast one node of the plurality of nodes.
 9. The system of claim 8,wherein one or more of the nodes are located at least one of a fansection, a compressor section, a combustor section and a turbine sectionof the gas turbine engine, and the first waveguide comprises a hollowmetallic waveguide.
 10. The system of claim 8, wherein the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller.
 11. The systemof claim 10, further comprising a dielectric disk in the first waveguideproximate to the membrane, wherein the dielectric disk is configured togenerate a plurality of acoustic pressure waves to mechanically vibratethe membrane responsive to the pulse train broadcast through the firstwaveguide, and the at least one node comprises an effector node.
 12. Thesystem of claim 8, wherein the at least one node comprises an oscillatorand a modulator configured to vibrate the membrane based on a sensorresponse, and the radio frequency transceiver is configured to detectvibration of the membrane.
 13. The system of claim 12, wherein the radiofrequency transceiver is configured to output a pulse train to broadcastwithin the first waveguide responsive to the controller, and furthercomprising a dielectric ring in the first waveguide proximate to themembrane, wherein the dielectric ring is configured to generate aplurality of acoustic pressure waves to mechanically vibrate themembrane responsive to the pulse train broadcast through the firstwaveguide, and the at least one node comprises an effector and sensornode.
 14. A method of establishing electromagnetic communication, themethod comprising: configuring a network of a plurality of nodes tocommunicate through one or more electromagnetic signals; initiatingcommunication between a controller and the network of nodes through theone or more electromagnetic signals; guiding transmission of the one ormore electromagnetic signals in a plurality of waveguides between thecontroller and one or more of the nodes; propagating a portion of theone or more electromagnetic signals through a radio frequencytransceiver configured to establish communication between the controllerand a first waveguide of the plurality of waveguides, and a membraneconfigured to support communication between the first waveguide and atleast one node of the plurality of nodes.
 15. The method of claim 14,wherein the first waveguide comprises a hollow metallic waveguide. 16.The method of claim 14, further comprising outputting a pulse train fromthe radio frequency transceiver to broadcast within the first waveguideresponsive to the controller.
 17. The method of claim 16, wherein adielectric disk in the first waveguide is proximate to the membrane, andfurther comprising generating a plurality of acoustic pressure waves tomechanically vibrate the membrane responsive to the pulse trainbroadcast through the first waveguide and the dielectric disk, and theat least one node comprises an effector node.
 18. The method of claim14, wherein the at least one node comprises an oscillator and amodulator, and further comprising: vibrating the membrane based on asensor response modulated with a carrier frequency of the oscillator bythe modulator; and detecting vibration of the membrane by the radiofrequency transceiver.
 19. The method of claim 18, further comprisingoutputting a pulse train by the radio frequency transceiver to broadcastwithin the first waveguide responsive to the controller.
 20. The methodof claim 19, wherein a dielectric ring in the first waveguide isproximate to the membrane, and further comprising generating a pluralityof acoustic pressure waves by the dielectric ring to mechanicallyvibrate the membrane responsive to the pulse train broadcast through thefirst waveguide, and the at least one node comprises an effector andsensor node.